1. Field of the Invention:
This invention relates to a grout material suitable for forming a cut-off zone in the ground such as a sand layer, a gravel layer, a silt layer, a soft rock layer and a hard rock layer and for improving a cut-off property of a concrete structure such as a concrete dam and a concrete building, an earth structure such as an embankment and an earth dam and a stone masonry structure or the like and a grouting method using the same.
2. Description of the Prior Art:
Some of grouting methods for forming a cut-off zone in the permeable ground such as a sand layer, a gravel layer, a silt layer, a soft rock layer and a hard rock layer have been disclosed in Japanese Patent Public Disclosure (KOKAI) Nos. 60-138112 and 61-211417. These grouting methods comprise the steps of boring a longitudinal hole in the ground, blowing a grout material such as cement, fly ash and silica in the form of powder into the longitudinal hole, and thereby grouting the grout material into an intustice between ground particles and cracks or the like. As a result, it is possible to give the cut-off property to the ground within a range where the grout material is grouted.
However, since cohesiveness and adhesiveness of the grout material used for the conventional grouting method of this type are high (grout material is liable to be adhesive and cohesive to each other), the grout material is inferior in permeability into the interstice between the ground particles and the cracks or the like, so that grouting of the grout material is not covered over the wide range around the hole.
Therefore, according to the conventional grouting method, since the cut-off property of a grouted portion is degraded, the number of holes per unit area has to increase to grout the grout material into a great number of portions.
Further, since the grout material used for the conventional grouting method of this type is hydrophilic to absorb water during the storage thereof, the quality of the grout material is rapidly degraded.